In this study, precious metal mixed oxides such as RhVOィイD24ィエD2, RhィイD22ィエD2MnOィイD24ィエD2, RhLaOィイD23ィエD2 have been prepared in small pores of support materials such as silica, USY zeolite, and catalytic properties of these catalysts have been investigated. RhVOィイD24ィエD2 could be prepared in NaY zeolite with the aid of the high mobility of VィイD22ィエD2OィイD25ィエD2 at high temperatures. Highly dispersed Rh metal was obtained by the reduction of the mixed oxides, and strong metal-oxide interaction (SMSI) was induced after the high-temperature reduction. Moreover, the mixed oxide catalysts could be regenerated by the calcination treatment, which leads to high-perfonace catalyst systems.Catalytic reactions such as CO hydrogenation, NィイD22ィエD2O decomposition, selective CO oxidation in hydrogen have been studied on these catalysts. In particular, RhVOィイD24ィエD2 supported on silica showed high activity and high selectivity to ethanol after the reduction of the mixed oxide. Dynamic behavior of molecules in the micropores of zeolite has also been studied.